Laser radiation techniques, generally, are known. Additionally, laser radiation equipment has been used in recent years in dentistry to replace certain mechanical dental tools which require the use of anesthetics to reduce the patient's sensitivity to pain. For example, U.S. Pat. No. 5,281,141 to Kowalyk discloses a method of removing tooth decay using a laser having an output wavelength which corresponds to the absorption band of a substance applied to the tooth decay.
Another example is disclosed in U.S. Pat. No. 5,194,005 to Levy. Levy discloses a method of applying laser radiation to a ceramic material to promote the growth of a crystal structure in that material and create a strong bond between the hydroxyapatite and the surrounding tooth material. Levy also discloses in U.S. Pat. No. 5,020,995 the use of a laser for removal of tooth and gum tissue at a wavelength of 1.06 micron together with a water/air mixture to control the thermal cutting action. In U.S. Pat. No. 5,151,029, Levy discloses use of a laser for removal or hardening of metal in a tooth. Various other patents address dental laser techniques.
Dentists have long used metal or dental amalgam materials to repair and protect teeth. Most of these materials, however, contain mercury. Further, because of the color and/or luster of the metals and amalgams, use of these materials in a visible portion of the mouth is generally cosmetically displeasing to many patients. Due to the poor cosmetics and concerns of potential mercury release associated with these metal and dental amalgam materials, there has been a recent movement in dentistry towards the use of non-metallic dental materials rather than metal or dental amalgam materials. For example, composite materials, which generally comprise microscopic particles of silica or quartz in a resin matrix, have been used more frequently in recent years. Also, the use of other non-metallic dental materials such as porcelain or ceramic restorations have been used as full crowns, inlays, and onlays in recent years.
These non-metallic dental materials, however, sometimes require removal. Due to differences in the coefficient of thermal expansion between the tooth and composite materials filled within a cavity in the tooth, for example, microscopic cracks may occur in the tooth. These cracks cause leakage in the tooth which may lead to pain and/or deterioration of the tooth. Also, non-metallic dental materials eventually wear during use due to the forces of mastication and have a tendency to stain over prolonged use. Therefore, when any of the above situations occur (or for other reasons), it is desirable for the non-metallic dental material to be fully or partially removed and replaced.